The present invention relates to a pasteurizer according to the generic clause of claim 1.
Pasteurizers of this kind are used, e.g. in the food-processing industry, for pasteurizing products, such as filled and sealed glass bottles.
For this purpose, the product is slowly passed through a tunnel on a transport conveyor, which normally has a width of several meters; in the tunnel the product is heated and then cooled down.
The products are normally fed to the pasteurizer on a fast-running feed conveyor, which has a markedly narrower width than the slower transport conveyor, and, after having been pasteurized, they are discharged by a fast-running discharge conveyor.
A pasteurizer of the type in question is known from DE2633384. The feed conveyor and the transport conveyor have provided between them a transfer surface implemented in the form of a sheet-metal plate or the like, so that the products can be pushed by means of a linear pusher from the feed conveyor across the plate onto the transport conveyor of the pasteurizer.
Whereas in DE2633384 only one row of products is supplied at a time, solutions are also known in the case of which the products are supplied on the feed conveyor in several rows side by side, the preceding bottles being pushed into the pasteurizer by said rows of bottles so that a pusher can be dispensed with.
These pasteurizers proved to be disadvantageous insofar as, if the supply of bottles is discontinued, e.g. for the purpose of affecting a change of product, products may remain on the plate between the feed conveyor and the transport conveyor, which must then be pushed by hand or which necessitates once more the use of a pusher for pushing them over the plate.
The plate has normally a width of more than half a meter so as to bridge the strurally conditioned gap between the feed conveyor and the transport conveyor of the pasteurizer.
In addition, DE 2508275 discloses a right-angled arrangement of single-track or multiple-track apron conveyors which are arranged on the same level. In this kind of arrangement, bottles or cans are transported from one apron conveyor onto the next, the second apron conveyor being arranged at right angles to the first one. In contrast to the transport conveyor of a pasteurizer and the feed conveyor thereof, both conveyors have the same width. In addition, they are also operated at the same speed, whereby a good transfer is obtained automatically, without any risk of falling over of the bottles or cans due to deceleration. In order to move the bottles or cans from one apron conveyor onto the next, a strip is arranged on the structure of the apron-type feed conveyor; by means of this strip bottles or cans can be transferred across the gap between the two conveyors. On the bottom side of the feed conveyor a cavity is formed in which a part of the deflection roll of the discharge conveyor is accommodated. The strip has a width corresponding to approximately less than half the diameter of a bottle to be transported. A pusher can be dipsensed with in this case.
It is the object of the present invention to provide a pasteurizer that can comprise a transport conveyor which is at least several times as broad as a feed conveyor and which moves at a much lower speed than the feed conveyor, but which still permits a trouble-free transfer of products even if only a small number of products or, temporarily, no products at all arrive, e.g. when a change of products takes place.
The characteristic features of the pasteurizer according to the present invention are that due to the arrangement of the feed conveyor and of the discharge conveyor, respectively, the transfer surface can be kept so short that, when a change of products takes place, no products or, if at all, only a small number of products will remain on said transfer surface.
A specially preferred embodiment is characterized in that a pusher is provided by means of which products remaining on the transfer surface, e.g. in the case of a change of products, can be pushed from the transfer surface onto the transport conveyor or onto the discharge conveyor. It will be of advantage, when this pusher is implemented as a rotary pusher. A rotary pusher operates, in comparison with a linear pusher, very reliably and it is less error-prone. Due to the fact that only one row of products is displaced over a pretty short distance, also a rotary pusher will be able to act on the products always at approximately the same height, provided that the pusher element, e.g. a rod, is applied in a circular segment located on a low level of the circular path of the rotary movement, since the pusher element will there vary only slightly in height during a rotary movement.